Process for the manufacture of diethylenetriamine and higher polyethylenepolyamines

ABSTRACT

The invention relates to a process for the manufacture of diethylenetriamine and higher polyethylenepolyamines by a transamination of ethylenediamine. The transamination is performed at a temperature from 135° C. to 180° C. at a pressure from 5 Mpa to 40 Mpa in the presence of hydrogen and a particulate catalysts containing 26 to 65% by weight of nickel on an oxide carrier. A high conversion degree of ethylenediamine and a high selectivity to form acyclic polyethylenepolyamines, such as diethylenetriamine are obtained by the process. The formation of cyclic amine compounds, e.g. piperazine, is low.

This application claims priority of PCT Application No.PCT/SE02/01351filed Jul. 5, 2002, and Swedish Patent Application No.0102590-7, filed Jul. 24, 2001.

The invention relates to a process for the manufacture ofdiethylenetriamine and higher polyethylenepolyamines by transaminationof ethylenediamine. The process exhibits a high conversion rate ofethylenediamine and a high selectivity to form acyclicpolyethylenepolyamines, such as diethylenetriamine. The formation ofcyclic amine compounds, e.g. piperazine, is low.

The most desirable products in the manufacture of ethylene amines areacyclic, preferably linear, ethylene amines containing primary andsecondary amino groups. Ethylene amines containing heterocyclic ringsare of less commercial interest. Thus, U.S. Pat. No. 4,568,746 disclosesa process for the production of an amine composition containing a highproportion of diethylenetriamine to piperazine, by transamination ofethylenediamine in the presence of a nickel, cobalt or rhodium catalystat temperatures between 170° C. and 210° C. and at a pressure of 1000psig. Specifically disclosed catalysts are Raney nickel and Raney cobaltcatalysts having a particle size of 20–60 μm, Rh supported on alumina,Ni/Re/B supported on silica and Ni/Zr supported on kieselguhr. The Raneynickel or Raney cobalt catalyst is unsuitable to use, since they arebrittle and difficult to handle. In addition, the small particle size ofthe Raney nickel or the Raney cobalt catalyst makes the catalystinexpedient to use in continuous methods as well as difficult to removefrom the reaction mixture. On the other hand, the catalysts having asupport give a comparatively high yield of piperazine.

The U.S. Pat. No. 5,410,086 also describes a method of controlling theratio of diethylenetriamine to piperazine, when transaminatingethylenediamine in the presence of hydrogen and a hydrogenationcatalyst, by adjusting the hydrogen concentration in the liquid reactionphase. Preferred hydrogenation catalysts are Raney nickel and Raneycobalt or a nickel/rhenium/boron catalyst.

The working examples disclose a transamination process ofethylenediamine, where the reaction is performed in a tube reactor whichhas been loaded with a catalyst containing 6.2 weight percent nickel,4.4 weight percent rhenium and 1.8 weight percent boron on a support.

Further, the publication GB 1 508 460 describes a process for themanufacture of diethylenetriamine by transamination of ethyleneamine inthe presence of a catalyst containing at least one transition metal ofgroup 8 of the Periodic Table of the Elements at a temperature from 100°C. to 150° C., the reaction being taken to a degree of conversion of 70%or less. Preferably the catalyst occupies at least 20% by volume of thereaction zone, and the reaction time is from 5 to 10 hours.

The general problem in these transamination processes of ethylenediamineto diethylenetriamine and higher polyethylenepolyamines is the fact thatthey at moderate temperatures and pressures result in too high aproportion of cyclic ethyleneamine compounds, such as piperazine, and/orthat the conversion degree of ethylenediamine is too low. Thus, there isa need for improvements leading to a high conversion degree ofethylenediamine and at the same time to a favourable ratio between thedesired acyclic polyethylenepolyamines and the cyclicpolyethylenepolyamines at favourable reaction conditions.

It has now been found that said objectives can be achieved by performingthe transamination process under mild reaction conditions in thepresence of a catalyst containing a high amount of metallic nickel on aporous oxide support. According to the present inventiondiethylenetriamine and higher acyclic polyethylenepolyamines aremanufactured by transamination of ethylenediamine at a temperature of135–180° C., preferably 150–165° C., at a pressure from 5 MPa to 40 MPa,preferably from 8–35 MPa, and in the presence of hydrogen and aparticulate catalyst containing 26–65%, preferably 30–65%, by weight ofmetallic nickel on a porous oxide support, preferably containingalumina, silica or a mixture thereof. Said transamination can beperformed batchwise but a continuous process is preferred. At atemperature from 145° C. to 165° C. and a conversion degree of 4 to 30%of ethylenediamine, high selectivities for acyclicpolyethylenepolyamines can be obtained. Thus, at a conversion degree of10%, the reaction mixture may have a weight ratio between acyclicpolyethylenepolyamine compounds and cyclic ethyleneamines of above 20:1and for 15% conversion degree of above 15:1. The corresponding ratiosobtained in the working examples of the U.S. Pat. No. 5,410,086 areessentially lower.

The catalytical active part of the catalyst of the present inventioncomprises a large amount of metallic nickel deposited on a porous oxidesupport. The catalyst may also contain supplementary, catalyticaleffective metals commonly used in amination processes, such as cobalt,iron, copper, palladium, or mixtures thereof. Said metals may be presentin a total metallic amount of 0,1% to 12% by weight of the amount ofmetallic nickel. Nickel and any supplementary metals are mainlyresponsible for the catalytic transamination effect.

The catalytic effect may also be promoted by the presence of a minoramount of another metal to achieve e.g. improved selectivity for thedesired products. These promoters may be present in a total metallicamount of 0.1% to 15% by weight of the amount of metallic nickel.Examples of suitable promoters are calcium, magnesium, strontium,lithium, sodium, potassium, barium, cesium, tungsten, iron, ruthenium,zinc, uranium, titanium, rhodium, palladium, platinum, iridium, osmium,silver, gold, molybdenum, rhenium, cadmium, lead, rubidium, boron andmanganese. Thus, for example rhenium has a pronounced positive effect onboth the selectivity and the conversion degree, while ruthenium has atendency to decrease the conversion degree but a strong selectivity forthe formation of acyclic polyethylene-polyamines.

Examples of suitable porous oxide supports are silica or various formsof alumina, for example alfa, delta, theta or gammaforms or mixturesthereof. Preferably the content of alumina is at least 25% by weight ofthe support. The support may also contain minor amounts of other oxidicmaterials, such as titania, magnesia and zirconia. Especially preferredare alumina or combinations between alumina and silica containing atleast 25% by weight of alumina. The inner surface area of the supportmay vary from 20 to 1000, preferably from 40 to 400, square meters pergram support. The support normally constitutes between 30% and 74% byweight of the whole catalyst. In a preferred embodiment of the inventionthe transamination catalyst contains nickel promoted with ruthenium,rhenium, palladium or platinum on a porous support containing alumina ora combination of alumina and silica. The catalytic active area of thecatalyst is suitably from 10 to 70 square meters per gram of catalyst.Normally, the catalyst has such a particle size that at least 80%,preferably at least 95%, by weight, have a size between 0.1 and 10 mm,preferably between 0.2 and 5 mm.

The transamination catalyst may be prepared by first coprecipitating anickel salt and salts of any supplementary and/or promoting metals, forinstance a nitrate salt, on a granulated support according to theinvention, in an alkaline solution or by impregnating the granulatedsupport with the metal salts. Besides the nitrate salts the mostcommonly used metal salts are acetate, acetylacetonate,ammoniumsulphate, borate, bromide, carbonate, chloride, chromite,citrate, cyanide, 2-ethylhexanoate, fluoride, formate, hydroxide,hydroxyacetate, iodide, methoxide, 2-methoxyethoxide, nitrocylchloride,nitrocylnitrate, octanoate, oxalate, perchlorate, phosphate, sulfamate,sulphate and tetrafluoroborate. The precipitate and impregnate aresuitably washed with deionized water and pressed in molds or extruded.The granules obtained may then be dried in air and calcined in air at atemperature in the range from 200 to 1200° C., normally 300 to 500° C.,depending on the decomposition temperature of the salts used, until thesalts are transferred into oxides. Finally the metal oxides are reducedto metallic form in the presence of hydrogen at a temperature from 150to 600° C., depending on the metal oxides to be converted, until adesired degree of reduction is reached. In case the catalyst containstwo or more metals, a combined precipitation and impregnation method canbe used. Suitable catalyst preparation methods are further described inM. V. Twigg, J. T. Richardson, Appl. Catal. A 190 (2000) 61–72, E. Kiset al., Polyhedron 17, 1 (1998) 27–34 and A. Baiker, W. Richarz, Syn.Comm. 8(1) (1978) 27–32.

The transamination process may advantageously be performed bothcontinuously and batch-wise. In a continuous process hydrogen andethylenediamine are suitably passed as a gas and liquid mixture underpressure through a fixed or fluidised bed of the catalyst at the desiredtemperature. In case of a solid bed, at least 80%, preferably at least95% by weight of the catalyst particles normally have a size from 0.5 mmto 10 mm, preferably from 1 mm to 5 mm. In a fluidised bed, at least80%, preferably at least 95% by weight of the catalyst particles arefrom 0.1 mm to 2 mm, preferably from 0.2 to 1 mm. The reaction mixtureobtained contains transaminated products, such as diethylenetriamine,triethylenetetraamine and piperazine, unreacted ethylenediamine, ammoniaeliminated in the transamination reaction and hydrogen. The reactionmixture is normally worked up by first separating the low molecularweight compounds, hydrogen and ammonia, from unreacted ethylenediamineand the various transamination products, which are subjected tofractional distillation. Hydrogen and ethylenediamine are returned tothe process.

The hydrogen is present in the transamination process to ensure a highyield of desired acyclic polyethylenepolyamines and to inhibit or reducethe poisoning of the catalyst. Normally, the amount of hydrogen is from0.1 to 3 moles per mole of ethylenediamine. It is desirable to keephydrogen and ethylenediamine to an essential part in the liquid state.Thus, the pressure in the reactor will be dependent mainly on thereaction temperature, but also on the amounts of hydrogen andethylenediamine. Since the reaction temperature is moderate the pressurewill also be moderate and suitably between 5 MPa and 40 MPa, preferablybetween 8 and 35 MPa, and the temperature from 135° C. to 185° C.,preferably between 145° C. and 165° C. During these conditions theconversion degree of ethylenediamine is good and the selectivity forlinear polyethylenepolyamines is high.

EXAMPLE

A cage containing one of the catalysts according to Table I, was placedin an autoclave equipped with a stirrer and a temperature controldevice. The autoclave was then flushed with nitrogen gas and chargedwith 120 grams of ethylenediamine. After closing the autoclave, hydrogenwas introduced to a pressure of 30 bar and the reactor contenttemperature was increased to the reaction temperature during stirringand held at this temperature for 4 hours, whereupon the reaction wasstopped by reducing the temperature. The reaction mixture obtained wasanalysed with respect to ethylenediamine (EDA), diethylenetriamine(DETA), higher acyclic polyethylenepolyamines (HAM) and piperazinecompounds (PIP). The transamination results are shown in Table II.

TABLE I Transamination catalysts Other Nickel metals Catalytic CatalystTest Support % by % by active Size Amount No. % by weight weight weightarea m²/g mm g  1 Alumina, 100 55 — 31 1.6 10.2  2 Alumina, 100 55 — 311.6 9.1  3 Alumina, 100 47 — 14 3.2 10.2  4 Alumina, 100 47 — 14 3.210.0  5 Alumina, 100 47 — 14 3.2 10.0  6 Alumina, 50, 60 — 35 1.2 10.2silica, 50  7 Alumina, 50, 60 — 35 1.2 10.3 silica, 50  8 Alumina, 50,60 — 35 1.2 10.1 silica, 50  9 Silica, 100 38 — 32 1.2 10.2 10 Alumina,100 33 — 8 4.8 10.2 11 Alumina, 100 33 — 8 4.8 10.8 12 Alumina, 50/ 60Ru >35 1.2 9.8 silica 50 0.75¹⁾ 13 Alumina, 50/ 60 Ru >35 1.2 8.7 silica50 0.75¹⁾ 14 Alumina, 50/ 60 Ru 4.5¹⁾ >36 1.2 8.6 silica 50 15 Alumina,50/ 60 Re >35 1.2 8.0 silica 50 0.75²⁾ 16 Alumina, 50/ 60 Ru >35 1.2silica, 50 0.75³⁾ A alumina, 100 16 — 6 4.8 7.2 B Silica, 100 15 — 103.2 7.4 ¹⁾impregnated with ruthenium chloride ²⁾impregnated withammonium perrhenate ³⁾impregnated with ruthenium nitrosylnitrate

TABLE II Transamination results Transamination products Conversionweight % Weight Test No. Temp ° C. % EDA PIP DETA HAM ratio¹⁾  1 16027.3 11.8 71.6 16.4 7.5  2 155 11.3 7.5 84.6 7.6 12.3  3 170 38.4 15.862.6 21.3 5.3  4 162 20.4 9.1 78.6 12.0 10.0  5 160 15.0 4.9 87.7 7.219.5  6 150 9.1 3.9 92.1 3.7 24.3  7 152 15.1 6.0 86.7 7.1 15.6  8 16038.0 15.1 65.1 19.6 5.6  9 170 23.8 16.0 59.6 24.1 5.2 10 170 52.3 20.625.9 53.2 3.8 11 150 13.8 12.1 63.1 24.5 7.3 12 170 42.7 14.5 63.3 21.85.9 13 150 5.4 2.2 95.9 1.1 44.5 14 150 3.5 1.5 97.3 0.0 64.1 15 15015.4 5.8 84.3 14.5 16.1 16 150 11.2 4.0 89.2 6.3 23.6 A 170 5.5 32.8 588.3 2.0 B 170 2.8 28.5 66.4 3.7 2.5 ¹⁾DETA + HAM/PIP

From the results it is evident that the catalyst according to theinvention has a high activity already at 150° C. At temperatures about150–165° C. the catalysts according to the invention have highselectivities to the formation of diethylenetriamine andpolyethylenepolyamines as well as a satisfactory conversion degree. Thepresence of ruthenium improves the selectivity further, while rheniumincreases both the selectivity and the conversion degree. The lowtemperature also reduces the pressure where hydrogen is present inliquid form. The test A and B are comparison tests and show anunfavourable combination of low conversion degree and low selectivityfor the formation of acyclic compounds.

1. A process for the manufacture of diethylenetriamine and higher linearpolyethylenepolyamines by a transamination reaction of ethylenediaminewherein the reaction is performed at a temperature from about 135° C. toabout 180° C., at a pressure from about 5 MPa to about 40 Mpa, and inthe presence of hydrogen and a particulate catalyst comprising 26 toabout 65% by weight of metallic nickel on an porous oxide support.
 2. Aprocess according to claim 1 wherein the reaction temperature is from145° C. to 165° C.
 3. A process according to claim 1 wherein the porousoxide support contains alumina, silica or a mixture thereof, and theparticulate catalyst comprises about 30 to about 65% by weight ofmetallic nickel.
 4. A process according to claim 3 wherein the porousoxide support is alumina or a mixture of alumina and silica comprisingat least 25% by weight of alumina.
 5. A process according to claim 1wherein the catalyst has a particle size such that at least 80% byweight of the particles have a size from about 0.1 mm to about 10 mm. 6.A process according to claim 1 wherein the catalyst further comprises,in metallic form, cobalt, iron, copper, palladium or a mixture thereofin a total amount of about 0.1% to about 12% by weight of the amount ofmetallic nickel.
 7. A process according to claim 1 wherein the catalystfurther comprises a metal selected from the group consisting of calcium,magnesium, strontium, lithium, sodium, potassium, barium, cesium,tungsten, iron, ruthenium, zinc, uranium, titanium, rhodium, palladium,platinum, iridium, osmium, silver, gold, molybdenum, rhenium, cadmium,lead, rubidium, boron, manganese or a mixture thereof in a totalmetallic amount of about 0.1 to about 15% by weight of the amount ofmetallic nickel.
 8. A process accordIng to claim 7 wherein the metal isrhenium, ruthenium, palladium or platinum.
 9. A process according toclaim 1 wherein the process is a continuous process.
 10. A processaccording to claim 9 wherein the amination reaction is performed in atubular reactor having a fixed bed.
 11. The process of claim 1 whereinsaid higher linear polyethylenepolyamine is diethylenetriamine.